Maximum Frequency of LEDs

Thread Starter


Joined Nov 13, 2015
A basic question: transistors, diodes has maximum frequency rating. 1n4007 are slow, 1n5819 are fast and 1n34 are ultra fast diodes. What happens if I fed UHF signal to an ordinary LED? Does that glow? How much rectified voltage I get if I fed UHF 5V signal in a 1n4007?

Answer of these question helps me to make concept about diodes' frequency.


Joined Aug 27, 2009
The junction switching speed (forward/reverse recovery time) and device (internal) capacitance are major factors. Large power diodes are slow because there is more to move when the voltage polarity reverses. At UHF a diode with a large junction capacitance provides a short-cut across the junction taking the diode mainly out of the circuit in actual operation. This capacitance changes with the value of reverse voltage so it can be useful. Varicap